Through standard semiconductor processing, a variety of electronic devices can be manufactured, such as transistors and the like. Such processing can require steps such as masking, etching, dopant diffusion, and deposition. Accordingly, such processing can be complex and require expensive equipment.
While less expensive techniques have been developed, such as printing of semiconductor materials and devices, it can be difficult to utilize such techniques to manufacture viable memory devices. In particular, solid state memory devices often use floating gate transistors as the basic memory elements. Such elements require sufficient carrier mobility to allow for electron transport through a dielectric layer into the floating gate layer. Carrier mobility of printed semiconductor material, however, is relatively low, making it generally unsuitable for manufacture of floating gate transistors for use in memory devices.
One type of memory device is a programmable read only memory (PROM) device. To render them programmable, PROM devices are typically provided with an electrical connection in the form of a fusible link (fuse). To open the fuse, a relatively high electrical current is driven though the metal or polysilicon layer. The current heats the metal or polysilicon above its melting point, thereby breaking the conductive link and making the metal layer or polysilicon discontinuous. The PROM device is thus programmed via conducting and non-conducting patterns of fuses, which represent the logical 1's and logical 0's corresponding to the data to be stored in the memory device.
Conventional semiconductor methods can be utilized for manufacture of such a fuse for a memory device. For example, in one method disclosed in US 20040209404, a semiconductor fuse is manufactured by providing an insulating substrate, forming a titanium nitride layer over the insulating substrate, and forming a tungsten silicide layer over the titanium nitride layer. In this method, these layers are formed as follows: the insulating substrate is formed by thermally oxidizing a portion of a silicon substrate, the titanium nitride layer is formed by depositing a layer of titanium and annealing the titanium in an atmosphere containing nitrogen or by depositing a layer of titanium in an atmosphere containing nitrogen, and the tungsten silicide layer is formed by chemical vapor deposition. In addition, the tungsten silicide layer is patterned by a photolithographic pattern and etch process and the titanium nitride layer is patterned by a wet etch process using the patterned tungsten silicide layer as a hard mask. However, these and other manufacturing techniques can be difficult to implement and require complex and expensive equipment.
Accordingly, it is desirable to reduce the expense and difficulty in manufacturing fuse devices, memory devices, and related circuitry. It is also desirable to provide less expensive, reliable fuse elements, memory devices, and related circuitry.